Expanded metal mesh and tool for producing the same

ABSTRACT

The invention relates to expanded metal mesh consisting of mesh webs and nodes and to a tool for producing said expanded metal mesh. At least some of the mesh nodes are configured as predetermined breaking points ( 8, 9   a   , 9   b ). The expanded metal mesh is produced by a shear blade which has tooth bases of differing depths between the individual teeth on the blade profile.

BACKGROUND OF THE INVENTION

The invention relates to an expanded metal mesh and to a tool forproducing same.

Known is an expanded metal mesh comprising an e.g. rhombic or squaremesh in the furnished condition, the geometry of which automaticallycouples expansion lengthwise and contraction crosswise. This knownreaction results in such an expanded metal mesh still being difficult toshape to conform to surface areas having pronounced three-dimensionalcurvature even when the material is itemized, folded or nicked anddoubled.

An expanded metal mesh for plastic modelling as a reinforcement inlayfor a covering material in the form of curves, webs or strips featuringhigh conformity to complex three-dimensionally shapes for use e.g. asverge and edge weatherstripping is known from DE 36 42 063. Thiscovering material consists substantially of an elastomeric layer and theexpanded metal mesh serving as a reinforcing element. This expandedmetal mesh features an expansion of 50 to 150% lengthwise and ≦20%crosswise, each mutually excluding the other, as well as a return ≦5%.

Known from EP 0 797 486 is an expanded metal mesh permitting very goodplastic modelling. In this known expanded metal mesh, two nodesstaggered from row to row in the mesh are parted by a nick perpendicularto the actual expanded cut. One such expanded metal mesh excels by beingexcellently conducive to three-dimensional shaping.

Known in conclusion from DE 198 21 574.6 is a means of improving theexpansion response of the expanded metal mesh by creating an additionaltransverse corrugation in the sheet metal by either using trapzoidal orcorrugated sheet as the starting material or by producing the transversecorrugation in a flat expanded metal mesh in the course of fabrication,subsequent flat rolling then creating links in the mesh which are bentS-shaped.

The drawback in all of these known expanded metal meshes is that they donot permit cost-effective manufacture, they also being more difficult tohandle than normal expanded metal mesh.

The invention is thus based on the objective of providing an expandedmetal mesh for cost-effective manufacture whilst permitting expansion intwo directions or at least no crosswise contraction in the presence oflengthwise expansion. A further objective of the invention is to providea tool for cost-effective manufacture of expanded metal mesh.

SUMMARY OF THE INVENTION

The expanded metal mesh in accordance with the invention ischaracterized by it being cut, for example, so that certain links remainjoined merely ultrathin, resulting in some of the nodes in the meshbeing configured as designed break points. Now, manufacture is the sameas for normal expanded metal mesh and the resulting expanded metal meshcan be handled and worked just as easily as normal expanded metal mesh.More particularly, the expanded metal mesh in accordance with theinvention has a uniform smooth surface with no risk of snagging, as isthe case, for example, with an expanded metal mesh in accordance with EP0 797 486 in which nodes in the mesh are parted by a nick perpendicularto the actual expanded cut.

The mesh in accordance with the invention can be filled out or coatedwith curing or elastomeric polymerizing or dry substances or compoundsand thus are useful e.g. as lathing as well as in roofing applicationsas products having become popular as “lead replacements”. Furtherpossible applications include:

1. spacers for cavity claddings,

2. tailored packings for spherical objects and the like,

3. drying grids and filter cages for industrial and domestic purposes,

4. mattings as employed in automotive repair as a replacement forglass-fiber plastics.

Further applications are conceivable in which forces need to be absorbedin an overload situation such as e.g. in guards on rotating machines orhighway safety fencing.

It is good practice to configure the nodes in the mesh in accordancewith the invention as a regular sequence of designed break points, by,for example, making every second or two from three nodes a designedbreak point staggered from row to row in the mesh.

Another variant consists of configuring the mesh, at least in localizedportions thereof, throughout with designed break points, wherebymarginal zones may be configured without designed break points toprevent unwanted tearing. To increase the stability and strength suchmeshes may be connected to each other at an angle and more particularlyat right angles and at the junctions.

The mesh in accordance with the invention including some nodesconfigured as designed break points is also combinable with an expandedmetal having an improved expansion response in accordance with DE 198 21574.6. Starting with trapezoidal, corrugated or similar shaped sheetmetal the nicks are incorporated in the mesh so that selected linksremain connected to each other only by ultrathin locations to thus formthe designed break points. The junctions at these modes configured inthe mesh as designed break points are, however, sufficiently rugged tobreak only when shaping as specified is done.

The weakened designed break nodes in the mesh may be produced with aconventional tool by setting a deeper cutting depth already duringmanufacture, although such a conventional tool may be used, however, toproduce only designed break nodes throughout in the complete mesh.

Should, however, designed break points be required only in a regularsequence, for example only at every second or third node, this can bedone with a tool having differingly deep gullets, such a tool producingin a “normal” cutting depth simultaneously conventional nodes anddesigned break nodes at the locations with less deep gullets. Instead ofdesigned break nodes, a smooth parting of some nodes may result withless deep gullets in obtaining a mesh as set forth in EP 0 797 486, i.e.a mesh in which every second and/or third node is parted staggered fromrow to row of the mesh, resulting in a mesh which can be excellentlyformed spherical.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be detailed with reference to the attacheddrawings in which:

FIG. 1 is a diagrammatic side view in perspective of how an expandedmetal mesh is produced;

FIG. 2 is a diagrammatic view of a shear blade gulleted differingly indepth for producing an expanded metal mesh in accordance with theinvention;

FIG. 3 is a diagrammatic view in the direction A as shown in FIG. 1illustrating manufacture of an expanded metal mesh with a tool as shownin FIG. 2;

FIG. 4 is an illustration of an expanded metal mesh comprising analternating arrangement of normally connected links and near-partedlinks as produced by a shear blade as shown in FIG. 2;

FIG. 5 is an illustration of an expanded metal mesh corresponding tothat as shown in FIG. 4 but in a partly expanded condition;

FIG. 6 is an illustration of one variant of an expanded metal meshproduced by another blade action, likewise shown in partly expandedcondition;

FIG. 7 is an illustration of an expanded metal mesh in which two ofthree links in each case are configured as designed break points;

FIG. 8 is an illustration of two expanded metal meshes each placed onthe other at right angles, configured throughout with designed breakpoints;

DETAILED DESCRIPTION

Referring now to FIG. 1 there is illustrated how an expanded metal meshis conventionally produced. The sheet metal 20 to be expanded isadvanced incrementally over a cutting edge 21 forming a bottom blade. Atop blade 22 having a toothed face 23 is lowered on to the sheet metalstrip advanced over the cutting edge 22. The top blade 22 slits thesheet metal 20 along the cutting edge 21 and simultaneously slantinglydownsweeps the protruding sheet metal strip, in simultaneously expandingit, to form a half-mesh. On the next increment, the top blade is loweredby e.g. half a mesh width laterally staggered to thus complete the mesh.

Known types of tools for this purpose produce expanded metal meshcomprising, with no exception, solid nodes, or nodes differingly solidto only a slight degree, with straight links inbetween, or linksslightly corrugated at the most in producing a festooned mesh. In all ofthese prior art expanded metal meshes, including those havingregular/asymmetrical mesh shapes, the spacing between the individualnodes cannot be systematically varied, due to the de facto straightlinks. It is precisely this ability to vary the node spacing for thepurpose of shaping also localized portions in the mesh withsubstantially more freedom, e.g. spherically or hyperbolic whilstavoiding unwanted deformation of adjoining mesh portions, that is ofdecisive significance and now available cost-effectively for the firsttime by tools modified in accordance with the invention.

Producing an expanded metal mesh in accordance with the invention ismade possible by gulleting the shear blade differingly deep. One suchshear blade 1 having teeth 2 is evident, diagrammatically from FIG. 2.Whilst the tips 3 are all the same, only every second gullet 4 a isconfigured as wide as the tips 3, the remaining gullets 4 b beingconfigured less deep and narrower to thus permit production of anexpanded metal mesh 5 as shown in FIGS. 3 and 4 having alternatinglynormally connected links 6 a and near-parted links 6 b (designed breakpoints).

Referring now to FIG. 5 there is illustrated a similar expanded metalmesh 7 shown portionally expanded, the circles 8 designating near-partedlinks 6 b and the points 9 a and 9 b designating a formerly contiguousnode. Due to the mesh being enlarged an expansion of app 35% is achievedwithout crosswise contraction.

Referring now to FIG. 6 there is illustrated a similar expanded metalmesh 10 involving a different blade action by it being moved twice tothe right and twice to the left respectively in each case, as is evidentfrom the circles 11 designating the designed break points.

Referring now to FIG. 7 there is illustrated how near 100% expansion isachievable when two from three links in each case are configured asdesigned break points 12.

Referring now to FIG. 8 there is illustrated in conclusion a sandwicharrangement of two expanded metal meshes 13 a and 13 b each placed onthe other at right angles, configured with designed break points 14throughout or intermittently.

The sandwiched meshes may be cemented together by a potting compound.

With reference to FIGS. 2 to 8 the invention has been described inconjunction with expanded metal mesh. However, the invention lendsitself in principle to any type of perforated sheet metal. For instance,the expanded metal meshes 13 a and 13 b as shown in FIG. 8 could also beproduced from perforated sheet metal with near-square perforations andincorporating designed break points 14.

FIGS. 2 and 3 depicted one variant of the shear blade for producingexpanded metal mesh in accordance with the invention.

Tools having one or more of the aforementioned features now permit forthe first time cost-effective manufacture of expanded metal mesh for ahigh degree of three-dimensional conformability incorporating remainingsolid nodes and angled links joining the latter for the purpose ofvarying the node spacing systematically activatable.

What is claimed is:
 1. An expanded metal mesh comprising a network ofmesh links and mesh nodes, wherein the nodes are in a plurality of rowsthat extend in a first direction and the rows are spaced apart in asecond direction, which is transverse to the first direction, andwherein some of the nodes in a row are configured as break points, suchas to rupture on application of a predetermined tension to the mesh, andsome of the nodes in said row are configured to withstand saidpredetermined tension without rupturing.
 2. An expanded metal meshaccording to claim 1, wherein the nodes that are configured as breakpoints are distributed in a regular pattern.
 3. An expanded metal meshaccording to claim 2, wherein every second node in a row is configuredas a break point and the break points in successive rows are staggered.4. An expanded metal mesh according to claim 2, wherein, in a given row,two nodes out of three are configured as break points and, in successiverows, the groups of three nodes are staggered.
 5. An expanded metal meshaccording to claim 1, wherein nodes that are configured as break pointsare confined to a region of the mesh.
 6. An expanded metal meshaccording to claim 1, formed from a sheet of corrugated or trapezoidalmetal.
 7. An expanded metal mesh according to claim 1, formed from asheet of perforated metal.
 8. An expanded metal mesh according to claim1, wherein, in each of first and second successive rows, first andsecond nodes in each sequence of three nodes are configured as breakpoints and the third node in the sequence is configured to withstandsaid predetermined tension without rupturing, and the third node in eachsequence of three nodes in the first row is staggered from the thirdnodes in the sequences of three nodes in the second row.
 9. An expandedmetal mesh according to claim 1, having a first region containing nodesthat are configured as break points and a second region containing onlynodes that are configured to withstand said predetermined tensionwithout rupturing.
 10. An article of manufacture comprising: a firstexpanded metal mesh comprising a network of mesh links and mesh nodes,wherein the nodes are in a plurality of rows that extend in a firstdirection and the rows are spaced apart in a second direction, which istransverse to the first direction, and wherein some of the nodes in arow are configured as break points, such as to rupture upon applicationof a predetermined tension to the mesh in said second direction, andsome of the nodes in said row are configured to withstand saidpredetermined tension without rupturing, and a second expanded metalmesh comprising a network of mesh links and mesh nodes, wherein thenodes of the second mesh are in a plurality of rows that extend in athird direction, which is inclined to the first direction, and the rowsof nodes of the second mesh are spaced apart in a fourth direction,which is transverse to the third direction, and wherein the first andsecond meshes are in overlapping relationship.
 11. An article accordingto claim 10, wherein some of the nodes in a row of the second expandedmetal mesh are configured as break points, such as to rupture onapplication of said predetermined tension to the second expanded metalmesh, and some of the nodes in said row of the second expanded metalmesh are configured to withstand said predetermined tension withoutrupturing.
 12. An expanded metal mesh comprising a network of mesh linksand mesh nodes, wherein at least some of said nodes are configured asbreak points designed to rupture on strain of said mesh, and wherein twomeshes configured continuous or intermittent with designed break pointsare placed on the other at an angle.
 13. An expanded metal meshaccording to claim 12, wherein said nodes are configured in a regularsequence as designed break points.